When does the FSF own your code?

I think that is covered by requiring a license if copyright alone would not be enough. My FSF papers say that the "Developer hereby agrees that if he has or acquires hereafter [...] intellectual property interest dominating the work, [...] such dominating interest will not be used to undermine the effect of this assignment, i.e. the Foundation and the general public will be licensed to use, in that program or programs and their derivative works, without royalty or limitation, the subject matter of the dominating interest. This license provision will be binding on the assignees of, or other successort to, the dominating interest [...] nonexclusive, royalty free and non-cancellable. (Sorry for any typos, only have a paper copy here.)